Trissolcus teretis (Johnson, 1987) (Hymenoptera: Scelionidae) parasitism on Euschistus heros (Fabricius, 1798) and Diceraeus melacanthus Dallas, 1851 (Hemiptera: Pentatomidae) eggs at different temperatures

Abstract

Trissolcus teretis has been recorded to parasitize eggs not only of Euschistus heros and Diceraeus melacanthus but also of other stink bug species in the most important soybean producing countries of South America such as Brazil, Argentina as well as other countries of the Neotropical region. Despite several studies relating to its natural incidence and parasitism, the impact of different temperatures on biology and parasitism capacity of T. teretis on eggs of E. heros and D. melacanthus is practically unknown. Considering that biological traits can be highly influenced by temperature, research on T. teretis parasitism at different temperatures and hosts is of theoretical and practical interest. We therefore evaluated T. teretis parasitism and development on eggs of E. heros and D. melacanthus at 15ºC, 20ºC, 25ºC, and 30ºC. Temperature had an impact on the parasitoid reared on eggs of both studied hosts. Although we recorded parasitism at an extreme temperature of 15ºC, these conditions are unfavorable for T. teretis parasitism, impairing parasitoid biological traits, especially survival of larvae and adult parasitism. Therefore, for application in crop fields where temperatures of 15ºC or lower are common, additional studies are necessary to investigate the possible need to increase parasitoid numbers during releases or to choose smaller intervals between multiple releases.